Combined drill and oyster dredge



2 Shets-Sheet 1.

(No Model.)

v T. THOMAS, COMBINED DRILL AND OYSTER DRE'DGB. No. 589,047.

P atente d Aug. 3 1 1 897.

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I W E NTU yzm x THE nomus PETERS co. FHOTO-LITMO., wnsummou. u. o

(No Model.) 2 SheetsSheet 2. T. THOMAS.

.GOMBINED DRILL AND OYSTER DREDGE.

Patented Axig. 31, 1897;

w m/ w form all the requirements or the ordinary UNITED STATES ATENTFFrcE.

THOMAS THOMAS, OF N'E\V HAVEN, CONNECTICUT.

COMBINED DRILL AN D O Y STER DREDGE.

SPECIFICATION forming part of Letters Fatent No. 589,043, dated August 31, l

Application filed-January 16,1897. $erial No. 619,415. (No model.)

To aZZ whom it may concern:

Be it known that I, THOMAS THOMAS, a citi zen of the United States, anda resident of New Haven, in the countyof New Haven and State ofConnecticut, have. invented certain new and useful Improvements in aCombined Drill and Oyster Dredge, of which the'following is aspecification.

My invention relates to a device designed to rid oyster-beds of drillsor borers, and it is also adapted to take up oysters and perdredge.

Of all the enemies of the oyster with which theoyster-planter has tocontend none are so destructive, by reason of their size, and thereforedifficult of capture, as the oysterdrill, a small marine gasteropod thatbores holes through the shell of the oyster. Heretofore all efforts torid an oyster-bed of these pests has resulted in failure. I

My device'consists of a network structure provided with a forward bladeadapted to raise objects from the ground and deposit them on a screen,the meshes of which screen will allow drills to pass through into thebody portion or receptacle of the dredge, while oysters and other largerobjects will be carried over the screen and fall on the ground back ofsuch dredge.

To enable others to understand my inven tion, reference is had to theaccompanying drawings, in which- Figure 1 represents a perspective viewof my improved dredge with the cover or screen dropped into an inclinedposition in readiness to catch drills. Fig. 2 is a perspective View ofthe dredge with screen elevated, in which condition the device is usedto take oysters, also broken view of the draft-iron. Fig. 3 is aperspective View of the dredge with the screen thrown back. Fig. 4 is across-sectional view of the frame of the dredge and blade, end elevationof one end of said dredge, and one of the end frames of the screen in aninclined position, and broken view of the draft-iron. Fig. 5 is adetailend View of the screen-frame and sectional view of the upper rail of thedredge. Fig. 6 is a detail broken view of the screen-frame and sectionalView of the upper rail of the dredge.

'Its construction and operation are as follows: V I The dredge shown isa rectangular-shaped construction, whose'ends 1', back 2, and bottom 3are made of wire-netting, bounded by theiron frame 4.

v '5 is the wire screen, bounded by the rectangular frame 6. This screenis detachably hinged to the upper rail of the frame of the back 2 bymeans of the projections 7, Figs. 4,5, and 6, inserted in the lugs 8 ofsuch upper rail.

9 are claws mounted on the forward part of the screen to engage with thenetwork of the bottom of the dredge, Fig. 4, and thus prevent the screenbeing forced back under the weight of a body of oysters.

1O areears mounted upon the ends of the screen-frame, and they areprovided with the hole 11 to receive the ends of the threaded bolts 12,which bolts are inserted in threaded holes of the end frame of thedredge. This arrangement is used to maintain the screen in an elevatedposition when the dredge is used for the purpose of catching oysters.

13 is the blade fastened to the lower forward rail of the dredge-bottomby means of the rings 14.

15 is the draft-iron, attached to such blade.

In operating the device the screen is elevated, as shown at Fig. 2, andthe dredge thrown over and a haul made for oysters in order to see theircondition. If the'work of drills appear, then the screen is lowered, as

shown at Fig. Land the dredge returned to the bed, assuming, when inoperation, the position as shown. The blade 13 will scrape the surfaceof the ground clean of every kind and quality of material. The stones,oysters, and other matter too large to pass through the screen will becarried up the incline and over the back of the dredge by the force ofthe water, while the drills will fall through the screen into the dredgeand will remain there, as the meshes of the dredge-body are smaller thanthe drills, and from which they can be dumped out and destroyed when thedredge is hauled aboard. As the drills are heavy and pointed and themesh of the screen is fully large enough to take in full-grown drills,which are about one inch in length, it

will readily be seen, and which has also been practically demonstrated,that they will all pass through the screen before they reach the top ofthe incline.

If required, the back rail of the dredgeframe may extend above thescreen, as shown at Fig. 6, so as to hold any of the drills that mayhave passed over the screen and reached this point long enough to allowthem to fall through said screen at this point,butit is extremelydoubtful if any drills will be able to reach this point.

It will be understood that the size of the mesh of the screen will varyaccording to the ground to be worked. When the oysters are two or threeyears old ,or more, the mesh can be made larger and reduced for smalleroysters, always, however, maintaining a mesh large enough to catchfull-grown drills. For this purpose the screens are made readilyattachable and detachable from the dredge, as shown and previouslydescribed. This devicci. (2., the woven-wire holding-receptacle-can beattached to an ordinary oyster-dredge, in which case the screen would beelevated and the wire receptacle would take the place of the bags nowused forholding the oysters that pass over the blade of the ordinarydredge, in which case, also, the blade of the wire holding-receptaclecould be dispensed with.

It will be observed that the screen, sides, and bottom of my device aremade of woven wire. This is done because this material is cheaper andeasy to obtain; but it will be understood, however, thatperforated-metal plates can be substituted for such woven wire, and Ihold myself at liberty to do so, without departing from the spirit of myinvention. Also, if found desirable, more than one screen can be used.Also the inclination of the screen may be changed without departing fromthe spirit of my invention, the gist of which consists in a dredge forremoving drills from oyster-grounds by lifting the drills and othermatter from the surface of the ground and passing such matter over ascreen, the oysters and other matter passing over the screen, while thedrills fall through the same and into a receptacle for that purpose.

The object of making the sides of my dredge of woven-wire netting isthat the water will readily pass through the dredge and not retard it.

The device as above described is cheap and effectual for the purposerequired, and it will work equally as well on a mud bottom as a hardone.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The combination, in a dredge of the character described, of aholding-receptacle and a screen overlying such receptacle adapted toretard drills and other objectionable matter and deposit them into thereceptacle, and permit larger bodies to pass freely over the saidscreen, for the purpose set forth.

2. The con'ibination, in a dredge of the character described, of aholding-receptacle and a screen overlying the same, and a blade orscraper to remove objects from the ground so that they may be depositedon the screen for the purpose described and set forth.

3. The combination, in a d redge,of the character described, of anopen-work holding-receptacle, an inclined open-work screen of largermesh adapted to close the mouth of such receptacle, a blade forward ofsaid receptacle so that objects may be removed from the surface of theground by such blade and be deposited on the said screen, the largerobjects passing over while the smaller ones like drills &c.--are forcedthrough the mesh of the said screen into the receptacle, for the purposeset forth.

et. The combination, in a dredge,of the character described, of anetwork receptacle, an overlying network screen of larger mesh than thereceptacle, said screen adapted to be readily attached to and bedetached from said receptacle, means whereby said screen can bemaintained in an elevated position, a forward blade adapted to scrapethe surface of the ground, removing oysters, drills &c., therefrom whichare passed over the said screen by the forward movement of the dredgewhen the said screen is in an inclined position, the drills and othersmall matter passing through the screen into the receptacle, while thelarger obj eets will be deposited back of said dredge, as described andfor the purpose set forth.

Signed at Bridgeport, in the county of Fairfield and State ofConnecticut, this (3th day of January, A. l). 1897.

THOMAS THOMAS. lVitnesses:

A. J. TANNER, M. J. KEANE.

